Pancreatic cancer

Colorectal cancer is the second most common cause of cancer-related death in the United States.

The incidence of EO-CRC, which refers to when people under 50 years of age develop the condition, has increased markedly in several wealthy countries.

One 2020 article in CA: A Cancer Journal for Clinicians suggested that over the course of the year, about 150,000 U.S. individuals would receive a diagnosis of colorectal cancer and about 53,200 would die as a result.

The authors also predicted about 18,000 cases of individuals younger than 50 years of age receiving a diagnosis of colorectal cancer, with 3,640 forecasted deaths in this population.

Compared with adults born in the U.S. around 1950, those born around 1990 have twice the risk of developing colon cancer and four times the risk of developing rectal cancer.

A new study in the journal Gut links drinking two or more SSBs per day in adulthood with a doubling in the risk of bowel cancer before the age of 50 years.

Researchers found that each daily SSB serving among adult women may be associated with a 16% higher risk of developing EO-CRC.

Also, the study found that each additional SSB serving per day among individuals aged 13–18 years may be linked to a 32% increase in the risk of developing EO-CRC.

Examples of SSBs include soft drinks, pre-packaged fruit drinks, energy drinks, and sports drinks. Sugary drinks are the leading source of added sugars in the American diet.

In fact, from 1977 to 2001, energy intake from SSBs increased by a whopping 135%.

Unique epidemiologic evidence

For this study, the researchers used data from 95,464 participants in the Nurses’ Health Study II. This is an ongoing monitoring study of 116,430 U.S. registered nurses, all women, who were aged 25–42 years when they enrolled in 1989.

Every 4 years beginning in 1991, the women in the study reported on what they ate and drank using validated food frequency questionnaires.

In 1998, researchers asked the participants to recall their health status and lifestyle habits as teenagers.

Also, 41,272 of the women reported on what they typically ate and drank as well as on the quantities of these items between 1960 and 1982. They were aged 13–18 years at this point.

The participants also gave information on potentially influential factors, including their family history of bowel cancer, their lifestyle habits, and any regular use of aspirin, nonsteroidal anti-inflammatory drugs, or vitamin supplements.

Over 24 years of monitoring, 109 women developed bowel cancer before the age of 50 years.

The study authors write that their findings “add unique epidemiologic evidence that SSB intake may partly contribute to the rapid increase of CRC in younger adults.”

Notes on the study

It is important for researchers to understand what is behind this increase, said study co-author Dr. Jeffrey Meyerhardt. He is the clinical director of the Gastrointestinal Cancer Center at the Dana-Farber Cancer Institute in Boston, MA.

“It is presumed that exposures early in life are contributing to this rise,” Dr. Meyerhardt told Medical News Today. “Studying exposures that can be prevented is [essential] to getting control of this rising health issue.”

Substituting SSBs with reduced-fat milk or whole milk appears to be beneficial, according to study co-author Dr. Yin Cao. She is an associate professor of surgery at the Washington University School of Medicine in St. Louis, MO.

“In this study,” she told us, “we showed [that] replacing one daily serving (8 oz) of SSBs with an equivalent amount of reduced-fat milk or total milk was associated with a 35–36% lower risk of EO-CRC.”

“During the second half of the 20th century, for which average U.S. per capita soft drink consumption has dramatically increased by ~500%, milk consumption has declined by half. Milk is a good source of calcium, a mineral found to be protective of colorectal cancer.”

“We postulate [that] low milk consumption could be plausibly linked with the increased risk of EO-CRC, and further research on this topic is in the pipeline.”

The researchers point to several limitations of their study. First, they caution that this was an observational study, which can only establish correlation, not cause. They also note that the majority of the participants were white women, so the findings may not apply to men or other ethnic groups.

Even so, the study provides insight into possible actions that public health leaders might take, Dr. Cao explained.

“Particularly in adolescence,” she wrote, “the immature and rapidly growing organs could be more susceptible to exposures that could lead to cancer development.”

“Campaigns, education programs, and interventions targeting the young population to reduce SSB intake and/or replace SSBs with other healthier beverages could help reduce the accrual of time at risk and convert this window of increased susceptibility into an opportunity for better health outcomes later in life.”

Two recent but separate studies have demonstrated how bitter melon and turmeric could be used to prevent, treat and reduce the progression of cancers.

Commonly called bitter melon, bitter gourd, African cucumber or balsam pear, Momordica charantia belongs to the plant family Cucurbitaceae. In Nigeria, bitter melon is called ndakdi in Dera; dagdaggi in Fula-Fulfulde; hashinashiap in Goemai; daddagu in Hausa; iliahia in Igala; akban ndene in Igbo (Ibuzo in Delta State); dagdagoo in Kanuri; akara aj, ejinrin nla, ejinrin weeri, ejirin-weewe or igbole aja in Yoruba.

Turmeric is a spice that comes from the root of Curcuma longa, a member of the ginger family, Zingaberaceae. In traditional medicine, turmeric has been used for its medicinal properties for various indications and through different routes of administration, including topically, orally, and by inhalation.

In Nigeria, it is called atale pupa in Yoruba; gangamau in Hausa; nwandumo in Ebonyi; ohu boboch in Enugu (Nkanu East); gigir in Tiv; magina in Kaduna; turi in Niger State; onjonigho in Cross River (Meo tribe).

Turmeric, also known as curcuma, produces a root that is used to produce the vibrant yellow spice used as a culinary spice so often used in curry dishes. Though native to India and parts of Asia, and is a relative of cardamom and ginger, turmeric has been domesticated in Nigeria. In Asia, turmeric is used to treat many health conditions and it has anti-inflammatory, antioxidant, and perhaps even anticancer properties.

Meanwhile, Prof. Ratna Ray from Saint Louis University in Missouri, United States (U.S.), and her colleagues, in a recent study on bitter melon, made an intriguing find. In experiments using mouse models, bitter melon extract appeared to be effective in preventing cancer tumours from growing and spreading.

The researchers report their findings in a study paper that now appears in the journal Cell Communication and Signaling. Ray grew up in India, so she was familiar not just with the culinary qualities of bitter melon, but also with its alleged medicinal properties.

This made her curious as to whether or not the plant also harbored properties that would make it an effective aid to anticancer treatments. She and her colleagues decided to put this to the test in a preliminary study by using bitter melon extract on various types of cancer cells — including breast, prostate, and head and neck cancer cells.

Laboratory tests showed that the extract stopped those cells from replicating, suggesting that it might be effective in preventing the spread of cancer. In further experiments using mouse models, the researchers found that the plant extract was able to reduce the incidence of tongue cancer.

So, in their new study, Prof. Ray and team tried to find out what might give bitter melon compounds an edge against cancer cells. This time, they used mouse models to study the mechanism through which bitter melon extract interacted with tumors of cancer of the mouth and tongue.

They saw that the extract interacted with molecules that allow glucose (simple sugar) and fat to travel around the body, in some cases “feeding” cancer cells and allowing them to thrive.

By interfering with those pathways, the bitter melon extract essentially stopped cancer tumors from growing, and it even led to the death of some of the cancer cells. Ray said: “All animal model studies that we’ve conducted are giving us similar results, an approximately 50 per cent reduction in tumor growth.”

Ray and colleagues explained that it remains unclear whether or not bitter melon would have the same effect in humans, but Prof., going forward, this is what they are aiming to find out.

“Our next step is to conduct a pilot study in [people with cancer] to see if bitter melon has clinical benefits and is a promising additional therapy to current treatments,” she noted.

Ray seemed convinced that the plant is, if nothing else, at least a positive contributor to personal health.“Some people take an apple a day, and I’d eat a bitter melon a day. I enjoy the taste,” she said.“Natural products play a critical role in the discovery and development of numerous drugs for the treatment of various types of deadly diseases, including cancer. Therefore, the use of natural products as preventive medicine is becoming increasingly important.”

Meanwhile, a recent literature review investigated whether turmeric may be useful for treating cancer. The authors concluded that it might be but noted that there are many challenges to overcome before it makes it to the clinic. The chemical in turmeric that most interests medical researchers is a polyphenol called diferuloylmethane, which is more commonly called curcumin. Most of the research into turmeric’s potential powers has focused on this chemical.

Over the years, researchers have pitted curcumin against a number of symptoms and conditions, including inflammation, metabolic syndrome, arthritis, liver disease, obesity, and neurodegenerative diseases, with varying levels of success.
Above all, though, scientists have focused on cancer. According to the authors of the recent review, of the 12,595 papers that researchers published on curcumin between 1924 and 2018, 37 per cent focus on cancer.

In the current review, which features in the journal Nutrients, the authors mainly focused on cell signaling pathways that play a role in cancer’s growth and development and how turmeric might influence them. Treatment for cancer has improved vastly over recent decades, but there is still a long path to tread before we can beat cancer. As the authors note, “the search for innovative and more effective drugs” is still vital work.

In their review, the scientists paid particular attention to research involving breast cancer, lung cancer, cancers of the blood, and cancers of the digestive system. The authors concluded: “Curcumin represents a promising candidate as an effective anticancer drug to be used alone or in combination with other drugs.”

According to the review, curcumin can influence a wide range of molecules that play a role in cancer, including transcription factors, which are vital for Deoxy ribonucleic Acid (DNA)/genetic material replication; growth factors; cytokines, which are important for cell signaling; and apoptotic proteins, which help control cell death.

Alongside the discussions surrounding curcumin’s molecular influence over cancer pathways, the authors also addressed the possible issues with using curcumin as a drug. For instance, they explain that if a person takes curcumin orally — in a turmeric latte, for example — the body rapidly breaks it down into metabolites. As a result, any active ingredients are unlikely to reach the site of a tumour.

With this in mind, some researchers are trying to design ways of delivering curcumin into the body and protecting it from undergoing metabolisation. For instance, researchers who encapsulated the chemical within a protein nanoparticle noted promising results in the laboratory and in rats.

Although scientists have published a great many papers on curcumin and cancer, there is a need for more work. Many of the studies in the current review are in vitro studies, which means that the researchers conducted them in laboratories using cells or tissues. Although this type of research is vital for understanding which interventions may or may not influence cancer, not all in vitro studies translate to humans.

Relatively few studies have tested turmeric’s or curcumin’s anticancer properties in humans, and the human studies that have taken place have been small-scale. However, aside from the difficulties and limited data, curcumin still has potential as an anticancer treatment.

Scientists are continuing to work on the problem. For instance, the authors mention two clinical trials that are underway, both of which aim to “evaluate the therapeutic effect of curcumin on the development of primary and metastatic breast cancer, as well as to estimate the risk of adverse events.”

They also refer to other ongoing studies in humans that are evaluating curcumin as a treatment for prostate cancer, cervical cancer, and lung nodules, among other diseases. The authors believe that curcumin belongs to “the most promising group of bioactive natural compounds, especially in the treatment of several cancer types.”

However, their praise for curcumin as an anticancer hero is tempered by the realities that their review has unearthed, and they end their paper on a low note: “Curcumin is not immune from side effects, such as nausea, diarrhea, headache, and yellow stool. Moreover, it showed poor bioavailability due to the fact of low absorption, rapid metabolism, and systemic elimination that limit its efficacy in diseases treatment. Further studies and clinical trials in humans are needed to validate curcumin as an effective anticancer agent.”

Meanwhile, an earlier study published in journal Current Pharmacology Reports established that besides diabetes, bitter melon is effective in treating other chronic diseases such as cancer and Human Immuno-deficiency Virus (HIV)/Acquired Immune Deficiency Syndrome (AIDS).

The study is titled “Bitter Melon as a Therapy for Diabetes, Inflammation, and Cancer: a Panacea?” The researchers noted: “Over the last few decades, multiple well-structured scientific studies have been performed to study the effects of bitter melon in various diseases. Some of the properties for which bitter melon has been studied include: antioxidant, anti-diabetic, anticancer, anti-inflammatory, antibacterial, antifungal, antiviral, anti-HIV, anthelmintic, hypotensive, anti-obesity, immuno-modulatory, anti-hyperlipidemic, hepato-protective, and neuro-protective activities. This review attempts to summarize the various literature findings regarding medicinal properties of bitter melon. With such strong scientific support on so many medicinal claims, bitter melon comes close to being considered a panacea.”

According to Food as Medicine: Functional Food Plants of Africa published 2017 by CRC Press, “…Dietary use of bitter melon or its juice decreases blood glucose levels, increases High Density Lipo-protein (HDL)/good cholesterol, and decreases triglyceride levels, thus exhibiting antiatherogenic qualities. Extract of bitter melon in supplement form has been widely used as a traditional medicine for diabetic patients.

When administered alone, it has a modest hypoglycemic effect at doses of at least 2000 mg/day. This botanical supplement enhances the cellular uptake of glucose and promotes insulin release, potentiating its effect, and in animal studies has been shown to increase the number of insulin-producing beta cells in diabetic animals. Bitter melon has also been found to reduce adiposity and oxidative stress in addition to reducing blood triglycerides and Low Density Lipo-proteins (LDL)/bad cholesterol.”

In last week’s Thursday’s edition of the Guardian Newspaper, I wrote generally on the fruit berries. Having done that I have also seen the richness of individual berries in the group of fruits in what is called berries. For this reason I have decided to write about four of the commonest fruits in this group.

It is important for us to know that there are berries in such shops as Shoprite, SPAR etc. In other words, these fruits can easily be found and bought here in Nigeria.

Strawberries are juicy and delicious nutrient-rich fruits, which are full of antioxidants. Minerals and vitamins commonly found in strawberries are potassium, calcium, magnesium, iron and vitamin CC.

Health benefits of strawberries

Boosts the immune system
Strawberries are a powerful source of vitamin C, which is an established immune booster. Vitamin C is also a well-known antioxidant. It is a fast working antioxidant, which effectively neutralises free radicals and contributes to the effectiveness of the Vitamin Antioxidant Defense System. Consumption of one serving of strawberries is sure to provide one half of our body’s daily requirement of vitamin C

Helps to prevent cancer
Vitamin C, the antioxidant neutralizes free radicals that would have destroyed cells and DNA and possibly cause cancer (vitamin C boosts the immune system). Ellagic acid is a phytonutrient that is also found in strawberry. Ellagic acid has been found to exhibit anti-cancer properties by suppressing cancer growth. Lutein and zeaxanthin (zeathanins) are free fatty acids also found in strawberry. They are antioxidants, which mop up free radicals and prevent oxidative stress damage of cells.

Ensures healthy vision
Strawberry, by its antioxidant function can help to prevent cataract formation. Cataract can lead to blindness in old age. The UV rays from the sun causes the release of free radicals from the protein in the lens. Sufficient vitamin C in the system neutralizes these free radicals and prevents damage to the lens of the eyes. Also, vitamin C functions in strengthening of the cornea and retina of the eye.

Cholesterol Lowering Effect
Strawberries are included in the list of heart-healthy foods. Ellagic acid and flavonoids in strawberries are antioxidants, which prevent the build up of plaques on the walls of arteries by the LDL (bad) cholesterol in the blood circulation. The anti-inflammatory effect of ellagic acid and flavonoids also prevent heart disease.

Reduction of inflammation
Arthritis, which is inflammation of the joints have also been found to respond positive to the antioxidants and phytochemicals in strawberries. An elevated C-reactive protein is an indication of inflammation. This CRP has been shown to decrease in those who consume strawberries regularly.

Effect on blood pressure
Potassium is richly found in strawberries – about 134mg per serving. Potassium is a buffer against the negative effect of sodium in the cell, which leads to a reduction of the blood pressure.

Increase intake of fibre
Fibre helps in the healthy digestion of food in the intestine and prevents conditions such as constipation and diverticulitis. Fibre also helps to reduce the absorption of glucose in the blood. Strawberries are a good source of fibre.

Many people with uterine fibroids have no symptoms, but others may experience pain and abnormal vaginal bleeding. For some people living with fibroids, the pain is intense enough to interfere with daily life.

Uterine fibroids are noncancerous growths that form inside the uterus. They can grow quite large and cause pain and pressure.

Fibroid pain usually occurs in the lower back or pelvis. Some people also experience stomach discomfort, intense cramps when menstruating, or pain during intercourse.

Easing the pain at home

There is little evidence that home remedies can ease fibroid pain. However, there are a few methods that people can try.

These include:

  • taking over-the-counter (OTC) medications, such as nonsteroidal anti-inflammatory drugs (NSAIDs)
  • using heating pads
  • practicing yoga or stretching
  • doing gentle exercise
  • eating a healthful diet

Some people may be interested in trying herbal remedies to shrink the fibroids and ease the pain. A 2013 Cochrane review analyzed previous research on the use of common herbal remedies — including Tripterygium wilfordii and Guizhi Fuling — to treat fibroids and their symptoms.

The researchers concluded that the quality of the data in the reviewed studies was insufficient to support the use of these herbal remedies.

Making lifestyle changes may be a more effective way for people to ease their fibroid pain.

Medication

A person can take medication to help ease fibroid pain. However, medication will not cure fibroids, and a person may require surgery later on.

These types of drugs may help ease fibroid symptoms:

  • Birth control pills: These can help reduce period pain. They may also make periods lighter, but they will not shrink fibroids.
  • A hormonal intrauterine device (IUD): This device releases progestin, which can help with painful, heavy periods but will not shrink fibroids.
  • Gonadotropin-releasing hormone (GnRH) agonists: These drugs counteract the effect of the hormones that regulate a person’s period. They can stop monthly bleeding and may help shrink fibroids.

The GnRH agonists may cause side effects, so doctors recommend that people take these for no longer than 6 months. After a person stops taking these drugs, the fibroids typically grow back.

Surgery

When fibroids cause pain, and medication does not work, a person may consider surgery. Doctors may recommend one of the following surgical procedures:

  • Myomectomy: A myomectomy is the removal of the fibroids from the uterus. This procedure does not remove the uterus, so it is still possible for the person to get pregnant afterward.
  • Ablation: This procedure involves using heat to destroy the fibroids. It will not remove the fibroids altogether, but they may shrink.
  • Laparoscopic power morcellation: For this procedure, a surgeon will make a tiny incision and insert a surgical instrument through it to break up fibroids. However, the Food and Drug Administration (FDA) caution that this treatment carries significant risks.
  • Hysterectomy: A hysterectomy removes the uterus. Sometimes, the surgeon will also remove the ovaries.

Other symptoms of fibroids

In addition to pain, some people experience the following symptoms:

  • very heavy bleeding
  • anemia from heavy periods
  • frequent bowel movements or urination
  • swelling or pressure in the stomach

Diagnosis

Many people find out that they have fibroids during a routine pelvic exam. A doctor can often feel the fibroids in the uterus during the exam.

A doctor can also detect fibroids by performing imaging tests, such as:

  • ultrasounds
  • MRIs
  • X-rays
  • CT scans

A doctor may sometimes recommend a hysterosalpingogram, which uses dye to see the uterus during an X-ray, or a sonohysterogram, which uses a saline solution to enhance the view of the uterus during an ultrasound.

Causes

Doctors do not fully understand what causes fibroids, but some possible causes and risk factors include:

  • Genetics: Fibroids may run in families, and certain genetic mutations increase the risk of these growths.
  • Hormones: Estrogen, progesterone, and growth hormones may increase the risk. Therefore, people who take hormonal birth control or have growth hormone injections may be more likely to develop fibroids.
  • Nutritional imbalances: Some research suggests that there is an association between vitamin D deficiency and the development of fibroids.
  • Race and ethnicity: African American women appear to be more likely than white women to develop fibroids.
  • Obesity: People who have overweight or obesity are two to three times more likely to develop fibroids than those with a moderate body weight.

When to see a doctor

It is not possible for a doctor to diagnose fibroids based on a person’s symptoms alone.

Many other conditions, including infections, pregnancy loss, and cancer, may share some of the symptoms of fibroids, so it is important to see a doctor for unusual bleeding or pelvic pain.

A person who already knows that they have fibroids should see a doctor if they experience:

  • sudden worsening of symptoms
  • heavy bleeding
  • pressure or swelling in the abdomen
  • returning fibroid symptoms after fibroid surgery

Summary

Many people develop uterine fibroids without being aware of them. However, some individuals may experience severe pain and need surgery or other treatments.

A person experiencing fibroid pain can stretch, use heat, or take OTC medications, but if the pain does not improve, they should see a doctor.

A doctor can guide treatment decisions by helping a person weigh up the risks and benefits of various symptom management options.

A recent study has investigated links between hair products and breast cancer. The findings have caused a stir, so in this article, we put the results into perspective.

Overall, breast cancer affects around 1 in 8 women during their lifetime.

Although breast cancer incidenceTrusted Source rates among non-Hispanic white women have historically been higher than among non-Hispanic black women, in recent decades, the rate of breast cancer among black women has increased.

Today, the breast cancer rates among black and white women are similar. However, according to the authors of a new study:

“[B]lack women [are] more likely to be diagnosed with aggressive tumor subtypes and to die after a breast cancer diagnosis.”

Scientists are working to pin down all the risk factors associated with breast cancer, and they are eager to understand why race-related disparities occur.

The study, which now appears in the International Journal of Cancer, focuses on hair products. Specifically, the researchers investigated hair dye and chemical hair straighteners, which permanently or semipermanently “relax” the hair.

Hair dye and breast cancer

Over the years, a number of studies have hinted at hair products’ potential role in cancer. As the study authors explain, “Hair products contain more than 5,000 chemicals, including some with mutagenic and endocrine‐disrupting properties.”

Older studiesTrusted Source have shown that certain chemicals in hair dye can induce tumors in the mammary glands of rats.

However, studies that have searched for an association between hair products and breast cancer in human populations have produced inconsistent results.

The authors of the recent research, based at the National Institute of Environmental Health Sciences, set out to take a fresh look. They decided to include hair straighteners in their analysis because earlier studies have largely ignored them. Importantly, according to the authors, these straightening chemicals “are used predominately by women of African descent.”

Because hair product ingredients tend to vary depending on whether the manufacturers market them to white or black women, the authors wondered if this might play a part in the disparity in breast cancer.

To investigate, the researchers took data from the Sister Study. This dataset includes information from 50,884 women aged 35–74. The scientists followed the women for an average of 8.3 years. The participants had no personal history of breast cancer but at least one sister who had received a breast cancer diagnosis.

Headline statistics

As part of their analysis, the researchers accounted for a wide range of variables, including age, menopausal status, socioeconomic status, and reproductive history. Importantly, they also had access to information about participants’ use of hair care products.

They found that women who used hair dye regularly in the 12 months before enrolling in the study were 9% more likely to develop breast cancer.

Specifically, when the scientists assessed the use of permanent dyes, they found that women who used these products every 5–8 weeks or more had an increased risk of breast cancer. Among white women, the risk increased by 8%. Among black women, the risk increased by 60%.

The study authors found no significant links between breast cancer and the use of semipermanent or temporary dyes.

When they looked at chemical hair straighteners, they concluded that women who used them every 5–8 weeks or more had a 30% increased risk of breast cancer. In this case, there were no significant differences between white and black women, though it is worth noting that black women seemed to use these products more often.

Not all percentages are equal

It is important to put these figures into perspective. The percentages above describe relative risk, which publishers tend to focus on because the numbers appear more dramatic.

For instance, studies have shown that women who drink two or more alcoholic beverages per day have a 50% higher risk of developing breast cancer. In other words, over the course of a lifetime and compared with women who do not drink, these women are 50% more likely to develop breast cancer.

However, this does not mean that they have a 50% chance of developing breast cancer.

In the general population, women have a 12% risk of developing breast cancer in their lifetime. So, if we increase this risk by 50%, that brings the risk up to 18%. In this example, the absolute risk increase is 6%, which is the difference between 12% and 18%. Although this is a significant increase, it does not have the same psychological impact as 50%.

Returning to the hair product study, although the reported relative risk of a 60% increase in breast cancer risk among black women is a significant result, the absolute risk of a new cancer diagnosis in this study population was less than 1% per year.

This does not mean that the topic is not worth pursuing. Any increase in cancer risk is important, but understanding the statistics helps put the matter into perspective.

Study limitations

As with any observational study, it is impossible to determine whether or not a factor is causal. The observed relationship might be dependent on other factors that the analysis could not account for.

Another potential issue is that every participant in the study had at least one first-degree relative who has experienced breast cancer. As the authors explain, this “may limit the generalizability of these findings.”

However, taking everything into account, this is a large study, and the findings are worth following up.

“We are exposed to many things that could potentially contribute to breast cancer, and it is unlikely that any single factor explains a woman’s risk,” explains study co-author Dale Sandler, Ph.D. “While it is too early to make a firm recommendation, avoiding these chemicals might be one more thing women can do to reduce their risk of breast cancer.”

As the use of marijuana is increasing in the United States, researchers are asking whether the use of this substance — particularly smoking joints — is associated with an increased risk of any form of cancer, and, if so, which.

Marijuana is one of the most widely used drugs in the United States, with more than one in seven adults reporting that they used marijuana in 2017.

Statistical reports project that sales of cannabis for recreational purposes in the U.S. will amount to $11,670 million between 2014 and 2020.

According to recent researchTrusted Source, smoking a joint remains one of the main ways in which individuals use marijuana recreationally.

While specialists already know that smoking tobacco cigarettes is a top risk factor for many forms of cancer, it remains unclear whether smoking marijuana can increase cancer risk in a similar way.

To try to find out whether there is a link between recreational marijuana use and cancer, researchers from the Northern California Institute of Research and Education in San Francisco and other collaborating institutions recently conducted a systematic review and meta-analysis of studies assessing this potential association.

In their paper — which appears in JAMA Network OpenTrusted Source — the team notes that marijuana joints and tobacco cigarettes share many of the same potentially carcinogenic substances.

“Marijuana smoke and tobacco smoke share carcinogens, including toxic gases, reactive oxygen species, and polycyclic aromatic hydrocarbons, such as benzo[alpha]pyrene and phenols, which are 20 times higher in unfiltered marijuana than in cigarette smoke,” write first author Dr. Mehrnaz Ghasemiesfe and colleagues.

“Given that cancer is the second leading cause of death in the United States and smoking remains the largest preventable cause of cancer death (responsible for 28.6% of all cancer deaths in 2014), similar toxic effects of marijuana smoke and tobacco smoke may have important health implications,” they go on to emphasize.

‘Misinformation — a threat to public health’

Dr. Ghasemiesfe and team identified 25 studies assessing the link between marijuana use and the risk of developing different forms of cancer. More specifically, eight of these studies focused on lung cancer, nine looked at head and neck cancers, seven examined urogenital cancers, and four covered various other forms of cancer.

The studies found associations of different strengths between long-term marijuana use and various forms of cancer.

The researchers note that the study results regarding the link between marijuana lung cancer risk were mixed — so much so that they were unable to pool the data.

For head and neck cancer, the researchers concluded that “ever use,” which they define as exposure equivalent to smoking one joint a day for 1 year, did not appear to increase the risk, although the strength of the evidence was low. However, the studies produced mixed findings for heavier users.

There was insufficient evidence to link this drug to a heightened risk of nasopharyngeal carcinoma, oral cancer, or laryngeal, pharyngeal, and esophageal cancers.

Among urogenital cancers, the investigators found that individuals who had used marijuana for more than 10 years appeared to have a higher risk of testicular cancer — more specifically, testicular germ cell tumors. Once again, however, the strength of the existing evidence was low.

There was insufficient evidence that marijuana use was associated with an increased risk of other forms of cancer, including prostate, cervical, penile, and colorectal cancers.

Dr. Ghasemiesfe and colleagues note that the studies that they had access to had many limitations, including numerous methodological problems and an insufficient number of participants who reported high levels of marijuana use.

Going forward, the team suggests that there is an urgent need for better quality studies assessing the potential relationship between marijuana and cancer. The researchers conclude:

“Misinformation [on this topic] may constitute an additional threat to public health; cannabis is being increasingly marketed as a potential cure for cancer in the absence of evidence, with enormous engagement in this misinformation on social media, particularly in states that have legalized recreational use.”

“As marijuana smoking and other forms of marijuana use increase and evolve, it will be critical to develop a better understanding of the association of these different use behaviors with the development of cancers and other chronic conditions and to ensure accurate messaging to the public,” they add.